IS 2010 Lecture Notes - Lecture 11: Optical Disc Drive, Hard Disk Drive, Head Crash

• School: University of Utah
• Department: Operations & Information Systems
• Course: IS 2010
• Professor: Lucy Woolsey

Document Summary

Random-access memory (ram) holds and stores data that the computer is currently processing or running. Therefore, it is sometimes known as primary storage. Most ram uses temporary storage and loses all the contents when the computer is turned off. Examples are hard-disk drive, data can be retrieved when the computer is turned off. Media- the physical material that holds the data and programs. Capacity- measures how much a particular storage medium can hold. Storage device- hardware that reads data and programs from storage media. Access speed- the amount of time required by the storage device to retrieve data and programs. Hard disks save files by altering magnetic charges of the disk"s surface to represent 1s and 0s. Characters are represented by positive and negative charges using ascii and ebcdic or unicode binary codes. Density refers to how tightly these charges can be packed next to one another on a disk.